A conventional method of calculating an amount of current in battery cells has employed a method of detecting and integrating the current in each component using a single fixed detection resistor. This method generates heat due to the use of the single detection resistor, and specifically due to the current in the detection resistor when a long time has lapsed, so that the measurement of the current amount in the battery cells is lowered in precision.
A battery pack fuel gauging system using such a single detection resistor will be described with reference to FIG. 1.
Referring to FIG. 1, the existing battery pack fuel gauging system 100 comprises battery cells, a resistor 101 for detecting the current from the battery cells, and a main chip 102 detecting and integrating an amount of the detected current.
This battery pack fuel gauging system employs a method of detecting the current in the detection resistor 101 at the main chip 102 at constant time intervals, and continuously adding up the current.
However, in the method used in the conventional system, increase of the current in the detection resistor 101 during charging or discharging causes an increase in temperature, so that the measurement of the amount of current added up at the main chip 102 is lowered in precision, which has a bad influence on the surrounding components.
Thus, there is formed the necessity of preventing damage to the surrounding components caused by the generation of heat of the detection resistor 101 during charging or discharging, and detecting a more precise amount of battery current.